Since I started the project I have always wondered if it wouldnt be better to use polygons/triangles rather than voxels. To verify this decision, I created a reasonably complex test scene from multiple instances of the same block, and rendered the scene once with triangles using Display Lists & LOD and second using voxel raycasting (LOD inherently). The triangle block is created by exporting the voxels as polygon mesh, and then using Meshlab to reduce the triangles and create multiple LOD levels.
It turns out that triangles are much faster for a small to a medium number of instances (its about equal for 10x10x10 = 1000 instances) - but when having a large amount of 8000 instances (32 Million Triangles), 40x5x40 blocks, voxel raycasting is significantly faster ( 40 vs 13 fps ).
For triangles, I havent used any sophisticated occlusion culling. It would therefore be interesting to see how much more performance could be achieved using the voxel based umbra or the
software based rasterization presented by intel.
For the ones of you that would like to experiment with occlusion culling, the source & data of the polygon benchmark can be downloaded
[here].
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| Raycasting Outside |
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| Raycasting inside |
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| Triangles Outside |
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| Triangles inside |
